A personal computer as disclosed in Japanese Patent Unexamined Publication No. H3-116315 is an example of conventional information processing apparatus provided with a power supply section which controls supply of electric power to the recording section and the computer.
The conventional technology features that, in a battery/AC compatible computer system in which a resume mode and an automatic HDD (Hard-Disk Drive) power-OFF mode are set in the boot up system, it is provided with means to judge whether or not an AC adaptor is connected for supplying power to the system. Additionally, conventional technology includes means to stop the motor of the HDD if no AC adaptor is connected at the boot up. The HDD motor is brought to a halt only when no AC adaptor is connected, for the purpose of extending a battery operating time.
FIG. 9 is a flow chart showing a conventional initializing routine that follows a power-ON operation.
When power supply to an information processing apparatus is turned ON (S901), a microcomputer makes access to a BIOS-ROM, and the initializing routine shown in FIG. 9 is started.
Firstly, a set-up data stored in a battery-backup memory disposed in a clock module is referred to, in order to check if resume mode is enable, or not (S902).
If resume mode is not enable, viz. resume mode is disable, it executes normal boot up process (S907).
If resume mode is enable, then it checks whether or not an AC adaptor is connected (S903). At this moment, the microcomputer gets, from a power control microcomputer of intelligent power supply via an I/O controller, an information regarding the power supply status. Thus it can recognize whether the processing apparatus is being driven on a built-in main battery, or on an AC source.
If it is found that no AC adaptor is in use, viz. it is operated on the main battery, then setup data stored in a memory disposed within the clock module is referred to, in order to check whether or not the HDD auto power-OFF mode is enable (S904).
If the HDD auto power-OFF mode is enable, a HDD motor-OFF command is delivered to a HDD interface (S905) to set the HDD motor-OFF command in an interface register within the HDD interface. Upon receiving the HDD motor-OFF command set in the interface register of HDD interface, the HDD disconnects power supply to HDD motor to stop revolution of the HDD motor.
The microcomputer restores the processing apparatus to a state just before the disconnection of power supply, in accordance with the data of just before the power disconnection which is stored in the backup RAM (B-RAM). Thus the processing apparatus is set to a state where it can start from the state just before the power disconnection (S906).
After the processing apparatus is set to a state just before the power disconnection in accordance with the resume function described above, when an operator makes access to HDD through a keyboard, etc., the microcomputer releases the HDD motor-OFF command which has been set in the interface register within the HDD interface. When the HDD motor-OFF command is released, the power supply for driving HDD motor is released from the disconnected state; then, revolution of HDD motor is started and the HDD gets activated.
If no input operation is made through a keyboard, etc. within a certain predetermined time span while the HDD auto power-OFF mode is enable, the HDD motor-OFF command is set in the interface register within HDD interface, and the HDD motor stays halted in accordance with the command.
In the initializing routine at power ON shown in FIG. 9, if it is driven on an AC adaptor (Yes, at S903) despite an enable resume mode (Yes, at S902), a HDD motor-OFF command is not delivered and the HDD gets activated at the same time when the main switch of processing apparatus is turned ON.
In a case where the resume mode is enable (Yes, at S902) and it is driven on a built-in main battery, a HDD motor-OFF command is not delivered, like in the above case, if HDD auto power-OFF mode is disable (No, at S904). The HDD is activated at the same time when the main switch of processing apparatus is turned ON.
As described above, if a resume function is enable and a HDD auto power-OFF mode is enable in the conventional personal computers, HDD motor is not put into operation until a command making access to HDD is generated by an operator through a keyboard, etc., despite switching ON of the main switch of processing apparatus. So, the advantage of low-power operation due to HDD auto power-OFF function is increased; namely, idle power consumption by HDD can be saved and a battery can work for a longer time.
In the above-described conventional information processing apparatus, the power supply for driving a HDD motor can be cut in a status where a HDD auto power-OFF mode is enable and no AC adapter is connected at the time of switch-ON with a processing apparatus' main switch. Meanwhile, however, the power supply to the HDD interface is kept in ON state despite that it is not in use, incurring losses in the standby power consumption.